<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>后台登陆</title>

</head>
<body>

<form action ="index.php?act=login" method="post">
    <table align="center" style="margin-top:200px;">
        <tr>
            <td>用户名：</td><td><input type="text" name="user_name" /></td>
        </tr>
        <tr>
            <td>密码：</td><td><input type="password" name="pwd" /></td>
        </tr>
        <tr>
            <td>验证码：</td><td><input style="width:50px;" type="text" name="captcha" /><img src="index.php?act=login&op=captcha" />&nbsp;<a href="javascrip:void()" id="not-see">看不清</a></td>
        </tr>
        <tr>
           <td><input type="checkbox" name="login_escape" value="1" />一周免登陆</td> <td  align="right"><input type="submit" name="submit_admin" value="登陆" /></td>
        </tr>
        </table>
</form>
</body>
<script>
    document.getElementById('not-see').onclick= function(){
        document.getElementsByTagName('img')[0].src = "index.php?act=login&op=captcha&t="+Math.random();
    }
</script>
</html>